#!/usr/bin/env python3

import os
import sys
import logging
import django

DIR_PATH = os.path.dirname(os.path.abspath(__file__))
ROOT_PATH = os.path.abspath(os.path.join(DIR_PATH, '..', ''))
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'webvirtcloud.settings')
CERT = DIR_PATH + '/cert.pem'

if ROOT_PATH not in sys.path:
    sys.path.append(ROOT_PATH)

django.setup()

import re
import socket
from six.moves import http_cookies as Cookie
from webvirtcloud.settings import WS_PORT, WS_HOST, WS_CERT
from vrtManager.connection import CONN_SSH, CONN_SOCKET
from console.sshtunnels import SSHTunnels
from optparse import OptionParser

parser = OptionParser()

parser.add_option("-v",
                  "--verbose",
                  dest="verbose",
                  action="store_true",
                  help="Verbose mode",
                  default=False)

parser.add_option("-d",
                  "--debug",
                  dest="debug",
                  action="store_true",
                  help="Debug mode",
                  default=False)

parser.add_option("-H",
                  "--host",
                  dest="host",
                  action="store",
                  help="Listen host",
                  default=WS_HOST)

parser.add_option("-p",
                  "--port",
                  dest="port",
                  action="store",
                  help="Listen port",
                  default=WS_PORT or 6080)

parser.add_option("-c",
                  "--cert",
                  dest="cert",
                  action="store",
                  help="Certificate file path",
                  default=WS_CERT or CERT)

(options, args) = parser.parse_args()

FORMAT = "%(asctime)s - %(name)s - %(levelname)s : %(message)s"
if options.debug:
    logging.basicConfig(level=logging.DEBUG, format=FORMAT)
    options.verbose = True
elif options.verbose:
    logging.basicConfig(level=logging.INFO, format=FORMAT)
else:
    logging.basicConfig(level=logging.WARNING, format=FORMAT)

try:
    from websockify import WebSocketProxy
    try:
        from websockify import ProxyRequestHandler
    except ImportError:
        USE_HANDLER = False
    else:
        USE_HANDLER = True
except ImportError:
    try:
        from novnc.wsproxy import WebSocketProxy
    except ImportError:
        print('Unable to import a websockify implementation,\n please install one')
        sys.exit(1)
    else:
        USE_HANDLER = False


def get_connection_infos(token):
    from instances.models import Instance
    from vrtManager.instance import wvmInstance

    try:
        temptoken = token.split('-', 1)
        host = int(temptoken[0])
        uuid = temptoken[1]
        instance = Instance.objects.get(compute_id=host, uuid=uuid)
        conn = wvmInstance(instance.compute.hostname,
                           instance.compute.login,
                           instance.compute.password,
                           instance.compute.type,
                           instance.name)
        if instance.compute.hostname.count(':'):
            connhost = instance.compute.hostname.split(':')[0]
            connport = instance.compute.hostname.split(':')[1]
        else:
            connhost = instance.compute.hostname
            connport = 22
        connuser = instance.compute.login
        conntype = instance.compute.type
        console_host = conn.get_console_listen_addr()
        console_port = conn.get_console_port()
        console_socket = conn.get_console_socket()
    except Exception as e:
        logging.error(
            'Fail to retrieve console connection infos for token %s : %s' % (token, e))
        raise
    return (connhost, connport, connuser, conntype, console_host,
            console_port, console_socket)


class CompatibilityMixIn(object):
    def _new_client(self, daemon, socket_factory):
        # NoVNC uses it's own convention that forward token
        # from the request to a cookie header, we should check
        # also for this behavior
        hcookie = self.headers.get('cookie')

        if hcookie:
            cookie = Cookie.SimpleCookie()
            for hcookie_part in hcookie.split(';'):
                hcookie_part = hcookie_part.lstrip()
                try:
                    cookie.load(hcookie_part)
                except Cookie.CookieError:
                    # NOTE(stgleb): Do not print out cookie content
                    # for security reasons.
                    self.msg('Found malformed cookie')
                else:
                    if 'token' in cookie:
                        token = cookie['token'].value


        (connhost, connport, connuser, conntype, console_host, console_port,
         console_socket) = get_connection_infos(token)

        cnx_debug_msg = "Connection infos :\n"
        cnx_debug_msg += "- connhost : '%s'\n" % connhost
        cnx_debug_msg += "- connport : '%s'\n" % connport
        cnx_debug_msg += "- connuser : '%s'\n" % connuser
        cnx_debug_msg += "- conntype : '%s'\n" % conntype
        cnx_debug_msg += "- console_host : '%s'\n" % console_host
        cnx_debug_msg += "- console_port : '%s'\n" % console_port
        cnx_debug_msg += "- console_socket : '%s'\n" % console_socket
        logging.debug(cnx_debug_msg)

        if console_socket and conntype == CONN_SOCKET:
            # Local socket on local host
            self.msg('Try to open local socket %s' % console_socket)
            tsock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
            tsock.connect(console_socket)
        elif console_socket or re.match('^127\.', console_host):
            # Need tunnel to physical host
            if conntype != CONN_SSH:
                self.msg("Need a tunnel to access console but can't mount " +
                         "one because it's not a SSH host")
                raise Exception(self.msg)
            try:
                # generate a string with all placeholders to avoid TypeErrors
                # in sprintf
                # https://github.com/retspen/webvirtmgr/pull/497
                error_msg = "Try to open tunnel on %s@%s:%s on console %s:%s "
                error_msg += "(or socket %s)"
                self.msg(error_msg % (connuser, connhost, connport,
                                      console_host, console_port, console_socket))
                tunnel = SSHTunnels(connhost, connuser, connport,
                                 console_host, console_port, console_socket)
                fd = tunnel.open_new()
                tunnel.unlock()
                tsock = socket.fromfd(fd, socket.AF_INET, socket.SOCK_STREAM)
            except Exception as e:
                self.msg("Fail to open tunnel : %s" % e)
                raise
            self.msg("Tunnel opened")
        else:
            # Direct access
            self.msg("connecting to: %s:%s" % (connhost, console_port))
            tsock = socket_factory(connhost, console_port, connect=True)
            tunnel = None

        if self.verbose and not daemon:
            print(self.traffic_legend)

        # Start proxying
        try:
            self.msg("Start proxying")
            self.do_proxy(tsock)
        except Exception:
            if tunnel:
                self.vmsg(
                    "%s:%s (via %s@%s:%s) : Websocket client or Target closed" %
                    (console_host, console_port, connuser, connhost, connport))
                if tsock:
                    tsock.shutdown(socket.SHUT_RDWR)
                    tsock.close()
                tunnel.close_all()
            raise

if USE_HANDLER:
    class NovaProxyRequestHandler(ProxyRequestHandler, CompatibilityMixIn):
        def msg(self, *args, **kwargs):
            self.log_message(*args, **kwargs)

        def vmsg(self, *args, **kwargs):
            if self.verbose:
                self.msg(*args, **kwargs)

        def new_websocket_client(self):
            """
            Called after a new WebSocket connection has been established.
            """
            # Setup variable for compatibility
            daemon = self.server.daemon
            socket_factory = self.server.socket

            self._new_client(daemon, socket_factory)
else:
    class NovaWebSocketProxy(WebSocketProxy, CompatibilityMixIn):

        def new_client(self):
            """
            Called after a new WebSocket connection has been established.
            """
            # Setup variable for compatibility
            daemon = self.daemon
            socket_factory = self.socket

            self._new_client(daemon, socket_factory)

if __name__ == '__main__':
    if USE_HANDLER:
        # Create the WebSocketProxy with NovaProxyRequestHandler handler
        server = WebSocketProxy(RequestHandlerClass=NovaProxyRequestHandler,
                                listen_host=options.host,
                                listen_port=options.port,
                                source_is_ipv6=False,
                                verbose=options.verbose,
                                cert=options.cert,
                                key=None,
                                ssl_only=False,
                                daemon=False,
                                record=False,
                                web=False,
                                traffic=False,
                                target_host='ignore',
                                target_port='ignore',
                                wrap_mode='exit',
                                wrap_cmd=None)
    else:
        # Create the NovaWebSockets proxy
        server = NovaWebSocketProxy(listen_host=options.host,
                                    listen_port=options.port,
                                    source_is_ipv6=False,
                                    verbose=options.verbose,
                                    cert=options.cert,
                                    key=None,
                                    ssl_only=False,
                                    daemon=False,
                                    record=False,
                                    web=False,
                                    target_host='ignore',
                                    target_port='ignore',
                                    wrap_mode='exit',
                                    wrap_cmd=None)
    server.start_server()
